ColorRamp outputing unsollicited color variations despite using constant mode
I got it. I noticed that this happened even with only a #FF0000 background without any object on it, checked every possible option, and found a culprit: Output properties &gt; Post-processing &gt; Dither. I switched it to 0, and no more color variation. The only problem left is that colors are not always the exact ones, but they are always the same variation at least. #00FF00 becomes #01FF01, but it's always that, which is far better.